Apparatus for tuning musical instruments



L-C. DEAGAN.

APPARATUS FOR TUNING" MUSICAL INSTRUMENTS.

APPLICATION FILED MAYI4,1920.

1,402,219, A Patefited Jan. 3,1922.

PATENT OFFICE.

JOHN; G. DEAGAN, OF CHICAGO, ILLINOIS.

' APPAnA'rUsroR TUNING MUSICAL INSTRUMENTS.

Specification of Letters Patent.

Patented Jan. 3, 1922.

Original application filed August 6, 1917, Serial No. 184,584. Divided and this application filed May 14,

1920. Serial No. 381,264.

To all w from it may concern:

Be it known that 1, JOHN C. DEAGAN, citizen of the United States, residing at Chicago,in the county of Cook and State of Illinois, have invented a. certain new and useful improvement in ripparatustor Tun:

the tone of master pitch "is produced and the instrument is tuned'to'cause it to produce a similar tone'with apitch as nearly in unison therewith as possible, whereafter a testing tone similar tot-he tone of master pitch and the tone of the instrumentbeing tuned but differing in'pitch one, two, three,'or more vibrations per second from the pitch of the master tone, is concurrently produced: with the adjusted'toneot the musical instrument, the tone of master pitch being in the meantime silenced. If the testing tone differs one vibration from the tone of master pitch then the adjusted tone of the musical instrument being tuned should, to prove its accuracy,1comb1ne witl tlie testmg tone to produce one beat per second which is producible by such master and testing tones. If it takes longer than a second to produce a beat then the adjusted tone is too fiat and if it takes less than a second to produce a beat then the adjusted tone is too sharp and the musical instrument is adjusted until the adjusted tone, in combination with the testing tone, produces one heat per second. It the testing tone difiers two vibrations from the tone of master pitch then the adjusted tone should, to prove its accuracy, combine with the testing tone to produce two beats per second, and so on.

The instrument of my invention comprises a plurality of sound producing metallic solid bars one of which serves to produce a tone of selected master pitch and another of which produces a testing tone similar to but slightly differing in pitch from the tone of master pitch. There is desirably a plurality of bars for producing testing tones that diffor in pitch from each other as well as from the tone of master pitch. Sound dampers are preferably provided, one individual to each bar whereby the bars may be prevented from vibrating in sympath with sounded bars and whereby bars whic are sounded may be silenced. There is also provided 'a timing device for timing the beats jointly produced by the testing tone and the adjusted tone of the musical instrument that is being tuned. V

I will explain my invention more fully by reference to the accompanying drawings showing the preferred form of instrument with the aid of which the method of my invention may be practiced and in which drawings Fig. 1 is a front View of the instrument with the front cover of the casing removed, a part broken away; Fig. 2 is a, sectional view on line 22 of Fig. l with the cover of the casing closed; Fig. 3 is a view on line 33 of Fig. 1; Fig. 4 is a View on line 1+4 of Fig. 2; and Fig. 5 is'a view on line 55 of Fig. 4.

Like parts are indicated by similar characters of reference throughout the different figures. Q

The sound producing elements are preferably in the form of vertically hung vibrant solid metallic barsthat are to be struck by a hammer to set them in vibration. Bars land 2 are respectively capable of producing'tone'A having the international pitch of four hundred and thirty five vibrations per second and the orchestral pitch of four hundred and forty vibrations per second. In succession between bars 1 and 2 I preferably provide bars 3, l, 5 and 6 respectively producing tone A having pitches of four hundred and thirty six vibrations, four hundred and thirty seven vibrations, four hundred and thirty eight vibrations, and four hundred and thirty nine vibrations per second. These bars are suspended at nodal points upon the shanks of screws 7 projecting forwardly from a support 8 that is located within the cabinet 9. These bars are permitted to swing but are limited in their forward and backward movements by means of strips 10 upon the screws 11, and the cushions 12 upon the support 8. The tuning pendulum 15 is swung at the lower end of a chain 16 attached at 17 to the cabinet, the purpose of which is to time the beats jointly produced by the testing tone and the adjusted tone of the musical instrument order to accentuate the beats, resonators 18 may be provided behind the bars. 7

In tuning his musical instrument by the testing instrument as shown, the musician .bar' pertaining thereto. bar -of selected pitch. be silenced by its sets that bar into vibration (say bar 1) which will produce tone A of selected or master pitch and will cause his musical instrument m to sound a tone as nearly in unison with the tone of master pitch as possible,-whereafter the sounded bar of selected or master pitch is silenced and any other bar .(being then a testing bar) is soundedconcurrently with the sounding of the adjusted tone A of the instrument being tuned. If, for example, the selected testing bar is bar 6, it should combine with the adjusted tone A of the instrument being tuned to produce exactly four beats per second. If two bars intervene between the bar of master pitch and the testing bar, the adjusted tone should combine with the testing tone to produce three beats per second, and so on.

To silence the bar producing the tone of 'master'pitch and tosilence the other bars also, I provide damper 19 for each bar and meansindividual tg each damper for main taining it in silencing engagement with the ot only may the dampergbutthe other dampers prevent their bars fromsoundingin sympathy with any vibrating bar and the tone of the musical instrument that is being adjusted. In the arrangement illustrated, each damper is mounted in the cupped upper-end of a sleeve 20 mounted to move vertically upon the guiding sleeve 21. A. spring 22 is bottomed upon a pin 23 and has its upper end in pressing engagement with a bayonet pin 24 which is fixed with respect to the movable sleeve 20. -This pin operates in bayonet slots 25 in the fixed sleeve 21. By imparting suitable vertical and rotary movements to a sleeve 20, the corresponding damper may be maintained in or out of engagement with its bar, the spring 22 being adapted to hold its damper against the lower end of the corresponding bar. v

As as hitherto been stated the sounding bars are of solid metal to produce clear and definite tones, being in this respect superior to vibrating pipes and tuning forks. Moreover, the vibrations of these bars are not affected by the weather and the handling thereof will not throw them out of tune. The bars are made more perfectly to perform their functions by suspending them at their upper nodal points and having them normally free of contact elsewhere.

Having thus described my invention I claim as new and desire to secure by Letters Patent the following In an instrument employed in tuning musical instruments, the combination with solid metallic bars tuned to produce tones of nearly the same pitch, of dampers for said bars, means individual to each damper constantly tending to maintain it in silencing engagement with the related "bar, and means individual to each damper for releasably looking it out of engagement with the related bar.

In witness whereof, I hereunto subscribe my name this 25th day of March, A. D. 1920.

. JOHN C. DEAGAN. 

